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(11) | EP 0 851 333 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Cam and roller overcenter handle mechanism |
| (57) An overcenter mechanism (10) includes a housing (12) and a first shaft (14) mounted
on the housing. The first shaft has a first axis (34). A second shaft (20) is mounted
on the housing and the second shaft has a second axis (41) that parallels the first
axis. A lever (16) is attached to the first shaft, and the lever pivots about the
first axis in response to a force (Fop) applied to the lever. A cam (18) is attached to the first shaft, and the cam pivots
about the first axis. The cam has a cam surface including a first surface portion
(58) and a second surface portion (60). The first and second surface portions form
a cusp (62) therebetween. A cam follower (21) has a cam follower surface, and the
cam follower pivots about the second axis. A biasing member (26) urges the cam follower
surface against the cam surface in pressure contact. The cam follower and the pressure
contact cooperate with the cam to generate torque (τroller) on the cam until the cam follower surface contacts the cusp. The pressure contact
creates an instability about the cusp when the cusp contacts the cam follower surface,
and the torque pivots the cam so the cusp and the cam follower move away from each
other.
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